Hi soapcreek, and welcome to the Age 50+ forum.
My first recommendation for your dilemma is to talk to your doctor. (S)He can guide you, while taking into consideration any health issues, hormone fluctuations, family history, etc. that you may have.
Having said that, congratulations for maintaining your loss so far! I'm thinking that you are facing more than a plateau. Seven months is a long time to be on program without showing a loss. Normal plateaus can usually be broken with diligent journaling, calorie juggling, portion control, stepped up exercising, etc. You seem to be facing a bigger issue.
Phasing out of IP and choosing a different program may be just what you need to get back on the wagon. Why not hop around the boards here, check out the different forums, and see which group and weight loss program seems doable for you?
Whatever path you choose, remember that we are here for you during your journey.